1. Field of the Invention
This invention relates to a needle retraction apparatus for medical devices. One aspect of the invention relates to a new needle retraction apparatus that can be attached to or manufactured together with, or as an integral part of, a medical device such as a syringe, catheter, or other liquid infusion or collection device. Another aspect of the invention relates to a needle retraction apparatus that is rotationally activated and cam operated. Another aspect of the invention relates to a needle retraction apparatus for a liquid infusion or collection device, the apparatus having a body with a forwardly facing, rearwardly biased needle, in which needle retraction is initiated by manually rotating an actuator to interrupt a fluid flow path through the apparatus and reposition a needle retraction chamber. Another aspect of the invention relates to a frontal attachment for a liquid infusion or collection device that comprises a tubular retraction chamber external to any cavity of the device, which retraction chamber is repositioned by linear translational movement into alignment with a rearwardly biased needle holder. Another aspect of the invention relates to a needle retraction apparatus for a medical device such as, for example, a glass or plastic syringe, having a luer lock or other similarly effective connector and comprising a needle retraction chamber that is external to the syringe. Another aspect of the invention relates to a method for retracting a needle in a medical device whereby rotating an actuator and cam causes a needle retraction chamber to be repositioned into alignment with a rearwardly biased needle by linear translational movement.
2. Description of Related Art
Conventional syringes comprising a generally cylindrical barrel, a fixed needle projecting forwardly from the barrel, and a plunger slidably disposed inside the barrel through an opening in the rear of the barrel are well known. More recently, syringes have been made with a luer connector on the front of the barrel to which a needle hub is attachable to allow needles of different gauges or sizes to be used with a commonly configured barrel.
Even more recently, in an effort to control the spread of blood-borne pathogens and the incidence of contamination by contact with either exposed needles or bodily fluids, syringes having fixed or changeable needles have been designed to embody various “safety” elements. Such “safety” elements should desirably include a retractable needle, but many products marketed as having “safety” elements include, for example, covers or guards that are manually operated by medical personnel administering an injection to shield or cover the needle tip following removal of the needle from a patient.
Some previously disclosed needle retraction systems without changeable needles are activated either manually or automatically by application of a force upon completion of an injection to force the needle and needle tip back inside a retraction chamber. The only known syringe having a changeable, retractable needle does not have a conventional luer lock connection, and the retraction mechanism is activated by the application of a forwardly directed force to the plunger handle following removal of the needle from a patient, thereby exposing the needle and also exposing the user to the risk of needle-stick injury.
U.S. Publ. No. 2006/0155244 to Popov discloses a venipuncture device that rotates a port unit following needle retraction. The retraction chamber is disposed inside the medical device, is not part of the frontal attachment and remains stable while the port unit is moved rotationally relative to the retraction chamber following needle retraction. The frontal attachment disclosed there cannot be used with a generic luer lock syringe.
Although many advancements in syringe technology have been made in recent years, a frontal attachment is needed that can be used with a standard syringe having a conventional luer lock connector, that has a needle retraction chamber external to the syringe with which the frontal attachment is used, that offers the advantages of a retractable needle having sufficient retraction force to retract the needle while inserted into a patient, and that can be activated by the application of a rotational force to the syringe barrel, thereby moving the external retraction cavity into alignment with a rearwardly biased needle without applying a forwardly directed force to the plunger or the needle.